(Pallas, 1776) - White whale
The white whale, or beluga, is a robust animal. Its basic body shape is much like that of the narwhal; it has a small bulbous head with only a very short beak, no dorsal fin (instead, a shallow transversely nicked ridge runs along the midline of the back), small rounded flippers (with curled tips in adult males), and flukes that often have a convex trailing edge. White whales are “blubbery”; their bodies are supple and often wrinkled. There is often a visible neck. Because the cervical (neck) vertebrae arenot fused, white whales can move their necks more than most other cetaceans.
At birth, white whales are dark grey to brownish grey. They whiten increasingly as they age, reaching the pure white stage between 5 and 12 years of age.
The mouth generally contains 9, often heavily worn, teeth in each row of the upper jaw, and 8 in each row of the lower jaw.
Can be confused with
White whales can be confused with narwhals, which overlap in much of their range. The blotchy grey colour of narwhals, and the tusks of males of this species, should permit proper identification in most situations.
Most adult white whales are less than 5.5 m (males) or 4.1 m (females), and large animals may weighup to 1600 kg. Calves average about 1.6 m at birth.
White whales are found only in high latitudes of the Northern Hemisphere. They are widely distributed throughout the arctic and subarctic regions, mostly in shallow coastal waters; however, they do move into deep, offshore waters at times. White whales enter estuaries, and even rivers; there are a few records of solitary individuals ranging thousands of kilometres up various rivers. At least 15 stocks of white whales have been recognized, based on morphological, genetic, and distribution differences.
Biology and Behaviour
The highly gregarious white whale is most often found in groups up to about 15 individuals, but it is sometimes seen in aggregations of thousands. Pods are often segregated by age and sex; all-male groups and mixed aggregations, including females and young, are known.
In general, white whales are not showy at the surface and they do not often leap. These animals generally swim slowly. During the summer, they aggregate in large numbers in shallow estuaries, andat these times are very active. Their extreme loquaciousness has earned them the name “sea canary.”
Calves are born in spring to summer, between April and August, depending on the population.
Although various species of fish are considered to be the primary prey items, white whales also feed on a wide variety of mollusks and benthic invertebrates. Based on stomach contents, white whales are thought to feed mostly on or near the bottom.
There is a long history of direct hunting, both subsistence and commercial, of white whales by native peoples, Russians and Europeans. Commercial hunting is now uncommon, and most belugasare taken by natives for food. Recent catches by Alaskan, Canadian, Greenlandic, and Russian people combined, total several thousand per year. However, the population in most danger is no longer hunted. Beluga numbers in the St. Lawrence Estuary have declined, and the population is threatened primarily by the effects of chemical pollution. In other parts of their range, oil and gas activities have been a source of concern.